Of course, mankind benefits greatly from global warming. We get longer summers. And fast melting icecaps mean all of that Arctic oil will be easier to pull from the ocean floor. But it gets even better. According to a new study in The American Journal of Tropical Medicine and Hygiene, warmer nighttime temperatures are having a direct effect on the spread of humankind's greatest existential threat: the bubonic plague.

Scientists call the plague bacteria yersinia pestis, while we like to call it the Black Death. It's transmitted through flea-carrying rodents. So how are icecaps, fleas and the plague related? From the Times:

Cases have dropped over time, and the study concluded that rising nighttime temperatures since 1990 had helped. Warmer nights melt winter snowpacks earlier, leading to drier soil in rodent burrows. When the soil gets too dry, fleas die.

Still, the authors warn there could be fresh outbreaks as population growth pushes housing deeper into rural areas, closer to the infected animals.

Good news! And that last warning about fresh outbreaks should inspire you to do your part to save people. Throw that styrofoam cup right out of the window of your SUV, do some whippits and have a plastic bonfire in a National Park. It's the least you can do.